• Journal of the Korean Chemical Society
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• v.62 no.1
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• pp.52-63
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• 2018

The purpose of this study was to observe and analyze how pre-service secondary chemistry teachers conduct open-ended, free style, exploratory chemistry experiments. The study examined common difficulties and tendencies that teachers showed in the chemistry labs. The study also investigated how these teachers deal with their difficulties and obstacles, such as unexpected results and device errors. Next, the study explored how students' epistemic goals and considerations have been shaped and changed as they interacted with one another and participated in their experiments over time. The study suggests that it could be more effective to gradually decrease guided-features of the experiment by providing appropriate scaffolding, than to start with completely open-ended inquiry labs. The study also suggests that the establishment of epistemic agency among group members influences the way they conduct experiments. Consequently, it is necessary to consider how instructional design for open-ended inquiry labs may provide students with scaffolds to encourage their active participation and to build responsibility in group discussions.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.174-184
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• 2005

For the purpose of investigating the etiologic factors of early childhood caries in 18-month old infants which is an important period in pediatric dentistry, 234 infants of 18-month age and their first care-givers (mothers in most cases) who visited Ilsin Christian Hospital in Busan for the baby-care counseling and vaccination were examined. The oral examination was performed on the infants and their care-givers were individually interviewed about various items, and the data was statistically processed to yield the results as follows : 1. The prevalence rate of early childhood caries was 27.4%. 2. The percentage of the eldest child, the education level of the mother and monthly income were revealed lower in caries group infants. 3. The percentage of prolonged breast-feeding and the frequency of daily nursing was higher in early childhood caries group. 4. In early childhood caries group, the between-meal snacks were tend to be provided irregularly without predetermined time, and sugar containing snacks such as chocolates and candies were ranked in higher order whereas the fruits and milks were in lower ranks. 5. In early childhood caries group, the percentage of those performing the oral hygienic care was lower and the timing to start the toothbrushing was comparatively later. From the above results, it can be concluded that prolonged breast-feeding, poor snack habits and lower socioeconomic status act an important role in early childhood caries in 18-month old infants.

• KOMUNHWA
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• no.69
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• pp.91-111
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• 2007

This paper deals with the cultural and ideoligical background of the landscape designs on Joseon blue and white porcelains in the late Joseon period, and involves the government painters in the official kiln. Dongjeongchuwol-design (동정추월문), painted the full-moon night scene of Dongjeong lake on Jeseon blue and white porcelains, was in fashion in the late Joseon period. It didn't reflected the entirely realistic subject comparing to the painting circles at that time, but the principle and aesthetic appreciation of Royal family who leaded the official kiln. And Sansuinmul-design (산수인물화). painted the man of great caliber in the ancient history with mountain scenery, was similar to the painting manuals such as Gossihwabo (고씨화보) and Dangsihwabo (당시화보). It was a counterpart of Dongjeonchuwol-design on Joseon blue and white porcelains in the late Joseon period. These designs were painted into ogival-shaped frame (릉화창) on the blue and white porcelains in most cases, and adjusted to shape of porcelain. The landscape designs on Joseon blue and white porcelains became stereotyped, involving subjects of folk painting in the late 18th Century and the early 19th Century. This essay will be just a start to research into the landscape designs on blue and white porcelains in the late Joseon period, even though we seldom find works providing strict chronology among some works to the public.

• Journal of the Korean earth science society
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• v.38 no.3
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• pp.222-238
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• 2017

The purpose of this study is to explore a learning progression for integrated process skills in Earth science inquiry. For the purpose, a hypothetical learning progression (HLP) that capture how students' integrated process skills of science become sophisticated over time is developed through the literature review. This learning progression contains four components of the integrated process skills of science: designing inquiry, collecting data, analyzing data, and forming conclusion. Three hypothetico-deductive inquiry tasks of Earth science that start from recognition of the given problem to the forming conclusion are developed in order to document students' integrated process skills. A total of 126 students from middle, high, college level students participated in this study. After conducting the Earth science inquiry tasks, the integrated process skills of individual students are assessed by element based on HLP. In addition, the validation process for HLP was administered by applying the Rasch model using the students' assessment data. Finally, based on the analyzed data, the empirical learning progression (ELP) is developed by revising and supplementing the HLP. This study can help to find scaffolding methods to effectively improve the students' integrated process skills in Earth science inquiry class by identifying the factors that affect students' development of integrated process skills. It also provide implications for improving teachers' PCK of Earth science inquiry instruction.

• The Journal of Small Business Innovation
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• v.19 no.3
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• pp.1-16
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• 2016

Korean government had used public 'credit guarantee schemes' (CGS) as a counter-cyclical measure. However, it is still controversial about the effectiveness of policy financing on the SMEs. Criticism on policy financing involves the argument that supporting enterprises hampers competition and innovation of SMEs by increasing their dependence on the government and delays the exit of marginal firms. In this paper, we investigate how to effectively build up the rationale of running public CGSs. At the same time, we propose the ways to coexist of public credit guarantee and market-based private finance system for SMEs. First, CGS, as a counter-cyclical function, must coexist with the private financial system by compensating the market failure caused by pro-cyclical behavior of the private financial market. Second, CGS has the comparative advantages, compared to both the interest rate policy of the central bank and fiscal policy of the government. The credit guarantee is the symptomatic treatment that could revitalize the economy shortly by providing liquidity. Also, knowing that CGS is provided based on the leverage ratio defined by outstanding guarantee divided by capital fund, public 'credit guarantee' (CG) has an advantage that is free from the risk of government deficit. Third, the reason for existence of the CGS should be founded in supporting services for SMEs, available only in a public sector that is difficult to expect from private banks. In this regard, it is desirable to strengthen the publicness of credit guarantee over the support for start-ups, growing companies, the improvement of productivity, increase of exports, a long-term investment in facilities, the employment-creating businesses, and innovative enterprises.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.3
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• pp.143-149
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• 2012

With the increasing use of mobile phones, mobile game is emerging as an entertainment for move. Furthermore, smart phone is widely spread, so mobile game market is rapidly growing. According to "Republic of Korea 2010 Games White Paper" mobile game market is growing annual average 10% or more, and is expected to reach $ 9.8 billion in 2011. It is almost doubled compared to 2007. It became possible to realize complicated high-capacity game with mobile phone developed to smart phone. And at the same time, mobile game is associated with Social Network Services (SNS) and is worldwide growing as a part of 'mobile life'. Apple launched an application open market, App Store, in 2008, and mobile game industry welcomed an innovative turning point. Global smart phone application market (App Store) is opened, so Gameday is able to launch mobile games easily to the global market getting out of the domestic market. In addition, Apple App Store has the structure of sharing their revenue with the developer with 7 to 3 which is more favorable terms for the developer compared to supply mobile contents to the mobile carrier who monopolized the market in the past. The largest proportion of the current App Store application is game, and Gameday has the opportunity to make a significant leap forward by keeping pace with the new environment changes.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.20-23
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• 2016

Purpose Because of heart movement, PET image of heart is very blur. So, PET scan gated with ECG is necessary to improve a spatial resolution of heart PET image. In this study, we will evaluate a image quality of both gated $^{13}N-ammonia$ PET scan and non-gated one. Materials and Methods Before start a heart PET, we attached a ECG electrode on patients (n = 5, $aged=54{\pm}17$). And we started a list mode PET scan that used by a mCT40 PET/CT (siemens, germany) during 10 minute, injected $^{13}N-ammonia$ ($378{\pm}50MBq$) to a patients at same time. By using this list mode data, we reconstructed both gated PET image and non-gated PET image. Then we analysed a profiles of those images, performed a blind test, and subtracted a gated image on non-gated image. Results FWHM of a gated image is improved about 23% and there is a differency count distribution at a subtracted image from non-gated image to a gated image. But in case of blind test, everybody select the gated image as a better quality among each images. Conclusion As a result, we can find that image quality will improve by using gated PET scan. In additional, we can calculate a EF valve, apply QGS, QPS of PET. Therefore, the gated PET scan help improving an accuracy, applying a more information for a diagnosis.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.393-402
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• 2005

The field scale experiment was performed to examine the effect of plant coverage on the constructed wetland performance and recommend the optimum development and management of macrophyte communities. Four sets (each set of 0.88 ha) of wetland (0.8 ha) and pond (0.08 ha) systems were used. Water flowing into the Seokmoon estuarine reservoir from the Dangjin stream was pumped into wetland system. Water depth was maintained at 0.3 ${\sim}$ 0.5 m and hydraulic retention time was managed to about 2 ${\sim}$ 5 days; emergent plants were allowed to grow in the wetlands. After three growing seasons of the construction of wetlands, plant coverage was about 90%, even with no plantation, from bare soil surfaces at the initial stage. During the start up period of constructed wetlands, lower water levels should be maintained to avoid flooding newly plants, if wetland plants are to be started from germinating seeds. Effluent T-N concentration in low plant coverage wetland was higher in winter than high plant coverage wetland, whereas no T-P effluent concentration and removal efficiency difference was observed within 15% plant coverage. Dead vegetation affected nitrogen removal during winter because it is a source of organic carbon which is an essential parameter in denitrification. Biomass harvesting is not a realistic management option for most constructed wetland systems because it could only slightly increase the removal rate and provide a minor nitrogen removal pathway due to lack of organic carbon.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.1066-1070
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• 2002

10 male piglets at 5-6 weeks old with similar body weight (BW) were randomly assigned into the experimental (EXP) and control (CON) groups. The animals in EXP received intro-muscular injection with daidzein (DA) at the dose of 0.5 mg DA per kg start BW on day 1. The same procedures were repeated once every 3 days for eight times. The animals in CON received the injection only with same volume of control peanut oil. The animals were weighted on day 14 and 28 and the blood samples were obtained at different stages of the treatment for determining IGF-I levels and blood parameters. At the end of the experiment, the thymus and spleen from all the animals were surgically taken out and weighted. The results showed that BW and average daily gain (ADG) were not significantly different between the groups in term of the whole period, but ADG between days 14-28 was higher in EXP than in CON (p<0.05). On days 18, 21 and 25, IGF-I levels in EXP group were 20.53% (p<0.05), 15.92% (p>0.05) and 23.46% (p<0.05), respectively, higher than those in CON. The weights of thymus and spleen, the ratios of their weights to BW and red blood count (RBC) did not significantly differ between the groups at all stages. White blood count (WBC) in EXP steadily increased from day 22, reached its apex on day 24, which was higher than in CON (p<0.05) and its own levels on day 20 and 22 (p<0.01 or p<0.05), and remained higher on the later time (p=0.058). The results of percentage of T-Lymphocytes also demonstrated similar trend to WBC, but TLymphocyte transformation rate (%) appeared no significant change between the groups. In conclusion, Daidzein could stimulate male piglet growth and elevate serum IGF-I levels at certain stages of the treatment. It could also increase WBC and T-Lymphocyte rates, but had no significant impacts on RBC and T-Lymphocyte transformation rate.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.2
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• pp.79-84
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• 2014

To investigate the plating properties of a diethylene glycol-based Ag immersion plating solution containing citric acid, silver immersion plating was performed in a range from room temperature to $50^{\circ}C$ using sputtered Cu specimens. The used Cu specimens possessed surface structure with large numbers of pinholes which were created with over-acid etching. The Ag immersion plating performed at $40^{\circ}C$ exhibited that the pinholes and copper surface were completely filled with Ag just after 5 min mainly due to galvanic displacement reaction, indicating the best plating properties. Subsequently, the surface morphology of Ag-coated Cu became rougher as the plating time increased to 30 min because of the deposition of silver nanoparticles created by chemical reduction in the solution. The specimen that its overall surface was covered with silver indicated the start of oxidation at temperature higher than around $50^{\circ}C$ in air as compared with pure Cu, indicating enhanced anti-oxidation properties.